1. Field of Technology
Embodiments disclosed herein relate generally to a switching power converter and more specifically to adaptively detecting the gain of a bipolar junction transistor of the switching power converter.
2. Description of the Related Arts
Switching power converters include a power stage for delivering electrical power from a power source to a load and a switching device in the power stage. Bipolar junction transistors (BJTs) are commonly used semi-conductor switching devices in power electronic systems including switching-mode power supplies due to their low cost. Switching power converters using BJTs are used to deliver electrical power to electronic applications that use light emitting diodes (LEDs) such as architectural lighting, automotive head and tail lights, backlights for liquid crystal display devices, flashlights, etc. Compared to conventional lighting sources such as incandescent lamps and fluorescent lamps, LEDs have significant advantages, including high efficiency, good directionality, color stability, high reliability, long life time, small size, and environmental safety.
Some LED lamps (i.e. LED lightbulbs) may include a switching power converter to convert an AC input power to a DC power for driving the LEDs of the LED lamps. The LED lamps can be plugged into a lightbulb socket and dimmed by varying the average AC input power to the LED lamps with a dimmer switch. Most conventional dimmer switches are designed to work with conventional filament based lightbulbs and not LED lamps. Thus, it has become a challenge to design a LED lamp that can be dimmed with a conventional dimmer switch.